I would suggest a call to the Visitscotland offices - tourist information centre for Scotland - ask if they have any recommended operators suitable for the nature of your party as there are differnces in access to accommodation - ramped, lifts, on-site parking etc - although facilities comply to requirements of disabled access, due to the age of some properties and the room layouts, they may not all be suitable to you specific needs - do you need carers in adjoining rooms; do you want to stay in serviced apartments - this might be a nice option as it allows a real degree of flexibility and offers living space rather than just room space; is the coach to be used during the stay and so driver accommodation is needed, etc etc
VisitScotland is 0845 22 55 121
Edinburgh tattoo is 08707 555 118